Targeting strategy for generating the β^6Imutation.

(A) Top line depicts the structure of wild-type β-major genomic locus; the β^6I targeting vector is shown in the middle. The targeted allele with a retained PGK-neo cassette is depicted on the bottom line. Locations of external probe 166 and internal probe 169 are shown. (B) Comparison of DNA and amino acid sequences of mouse β-major globin and human β globin genes. (C) Southern blot analysis of genomic tail DNA derived from the progeny of β^6Iheterozygous mutant mice. (left) DNA digested with XbaI and hybridized with probe 166. (right) DNA digested with EcoRV and BglII and hybridized with probe 169.